Wow, I really like Lark. That was a surprise and I real shock coming from a man, honestly. I understand the concerns about the lack of history, but if we're frank, Delilah really only has one historical namesake and it's VERY negative. One of the most famous prostitutes of all time. Plus, it doesn't sound to alternative when you already have one child with a nature name.

Lark is spunky and strong (I love short names) and yet very feminine. I love it. I find this name actually very tame considering Xanthe, Artemis, and Delilah. You have a bunch of very romantic ancient ladies and then a bright nature name which to me, fits much better with Iris than any of the others.